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| 72 Bit DIMM |
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| 64 bits |
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| ECC | Spare |
Figure 1-11 Memory ProteXion
In the event that a chip failure on the DIMM is detected by memory scrubbing, the memory controller can
Memory scrubbing
Memory scrubbing is an automatic daily test of all the system memory that detects and reports memory errors that might be developing before they cause a server outage.
Memory scrubbing and Memory ProteXion work in conjunction with each other, but they do not require memory mirroring (as described below) to be enabled to work properly.
When a bit error is detected, memory scrubbing determines if the error is recoverable or not. If it is recoverable, Memory ProteXion is enabled and the data that was stored in the damaged locations is rewritten to a new location. The error is then reported so that preventative maintenance can be performed. As long as there are enough good locations to allow the proper operation of the server, no further action is taken other than recording the error in the error logs.
If the error is not recoverable, then memory scrubbing sends an error message to the Light Path Diagnostics, which then turns on the proper lights and LEDs to guide you to the defective DIMM. If memory mirroring is enabled, then the mirrored copy of the data in the damaged DIMM is used until the system is powered down and the DIMM replaced.